| 摘要 |
In drilling a hole using reverse circulation and the Venturi effect, drilling fluid is caused to flow through the annulus between the set of drill pipes and the hole and to rise under reduced pressure in the interior of the drill pipes to a level at which it is ejected outside the drill pipes, using a fluid diverting device connected in the set of drill pipes and which includes a Venturi tube, the device causing ejection of the fluid from the interior of the pipes, drilling fluid being pumped from the surface in the interior of the drill pipes to the device in which it is diverted into the Venturi tube to cause upward flow of fluid from the drill tool.
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